Core B will provide all PPG investigators with rat and human recombinant forms of SP-A produced in insect cells using baculovirus vectors. Mutant recombinant SP-A proteins from a large library of existing stocks are available. As new targets are identified, the Core will assist with design and generate mutant cDNAs and proteins. A panel of new S- and His-tagged SP-A NCRDs synthesized in E. coli are available for ligand binding experiments. Native rat SP-A purified from silica treated rats and human SP-A purified from the therapeutic lavage of alveolar proteinosis patients will be provided on request. Protein quality control assessments will include assessment of structural integrity and purity by gel electrophoresis, EDTA and endotoxin content, and functional capacities for sugar and phospholipid binding. All methods produce milligram quantities of high purity protein, which are suitable for biologic, spectroscopic and crystallographic applications. . RELEVANCE (See instructions): SP-A reagents are an integral part of experiments in all projects. The Core will provide reagents in a timely fashion, and assist with design and production of new reagent on demand.